Esters and process of producing same



' Patented Mar. 5, 1946 "2,395,93 Esrnn's AND raocnss F rao'nUcn G SAME 'Karl Miesche'r, ltiehen, and Jules Heer, Basel, Switzerland, ,assignors to CibaPhai-macentical Products me, Summit, N. .L, a corporation, of

New Jersey No Drawing. Original application July 17, 1939,

Serial No. 285,018. Divided'and this application November 15, 1943, Serial No'. 510,400. I Switzerland July 21, 1938 v 3 Claims. (01. 260-457) Inorganic esters of the I dihydroxystilbenes,

bearing a hydrocarbon substituent or substituents at the ethylene bridge, are described and claimed in our U. S. Patent No. 2,234,311.

The present invention relates .to the manufacture of new esters by'treating with an esterifying agent a phenolic compound of the polyphenylethane series having at least one aliphatic side chain branching from the ethane chain.

As parent materials there may be used .any compound of the dihydroxy phenyl ethane series which contains as a substituent in aand/or aposition a saturated or unsaturated, aliphatic side chain, for instance an alkyl residue or an alkylidene-residue.- If there are two substituents' these maybe identicalor different from each other. For example there may be used a:a'-diethyl- 4':4"-dihydroxy-diphenylethane, :a'-dipropyl- 2f 2f '-dihydroxy-.diphenylethane, 3 41(4' :4"-d1- hydroxy-diphenyl) 2:4 hexadiene, 2:3-(4':4"-" dihydroxy-diphenyl) -1:3-butadiene, 4:5-(4':4"-

dihydroxy-diphenyl) -3:5-octadiene. These parent materials may be made in a manner in itself known; see, for example, Dodds, Nature, volume 141. page 247 (1938). I

. Suitable esterifying agents are for example the corresponding acids themselves, their anhydrides, their halides or their estersderived from alcohols of low molecular weight (re-esterification) or the corresponding ketenes. The acid residue to be introduced may beinorganic or organic, for instance aliphatic, cycloaliphatic, aliphatic aromatic or aromatic; it may be substituted in any desired manner and may be straight chained or branched, saturated or unsaturated, for instance useful esterifying agents are those which are adapted to introduce the residue of the following acids: acetic, propionic, butyric, crotonic, valerianic, caproic, caprylic, capric. lauric, palmitic, stearic, hexahydrobenzoic, benzoic, phenylacetic, 1actic,succinic, phthalic, salicylic, formic. Other suitable esterifying agents are for instance inorganic acids, their halides, anhydrides or esters, for example phosphorusoxychloride, phosphoruspentachloride, phosphoruspentoxide, metaphosphorous acid, chlorosulfonic acid, toluene sulionic acid and hydrogen halides. The present application is primarily concerned with protecting those di-esters wherein the acid component is a phosphoric acid or sulfuric acid radical.

The process of esterification may follow known methods; preferably condensing agents such as pyridinelor quinoline are used. However, the method may be that 01 Schotten-Baumann.

For obtaining partially esteriiled dihydroxycompounds the completely.esteriiledv compounds may be partially saponifled, for instance by means of an alkaline agent in an alcohol under mild conditions. In the operation a re-esteriflca- 5 tion may occur under the catalytic eflect of the alkali so'that less than the equivalent quantity of alkali may be used. The reaction is consider- I ably accelerated with'conversioninto analcohol 'of higher molecular weight. On' the other hand the dihydroxy-compoundsmay be'directly partially acylated These partial esterifled products may be separated if desired from simultaneously produced completely esterified compounds, for

instance by means'ofdilute alkalihydroxide solucontaining free 'hydroxy groups may be again treated with an esteriiying agent adapted to introduce an acidresidue other than that already present; so that mixed polyesters may be obtained.

.1 parts: a:a'-diethyl -4't4"-dihydroxy-diphen- 3'0 yl-ethane is allowed to stand m 1 5 partsoipyrb dine and 4 parts of acetic anhydride-ior 24 hours at room temperature. The mass is then mixed cautiously, with cold water, whereupon :'-diethyl-4' :4"- dihydroxy-diphenylethane-diacetate separates in crystalline form. It may be recrystallized from dilute ethanol, melting point 136- 13'l C.

In similar manner the acetatefoi md-dipropyl- 2':2"-dihydroxydiphenyiethane' may be pre- Ea'ample 2 1 part of :s'-diethyl-4':4"-dihydroxy-diphen- 'yl-ethane is introduced into 15 parts oi pyridine containing 5 parts of propionic acid anhydride and then allowed to cool'and mixed with water. An oil separates which is extracted by ether, the ethereal solution being washed successively with N-sulfuric acid, water and N/lfl-caustidsoda solution. The dipropionate remains on evaporation of the ether and may be recrystallized irom aqueous ethanol; melting "point 123-129 C.

To a mixture 0! azd-diethyligif dihydroxydiphenylethane-dipropionate with'100 parts of methanol is added in-thecold crop by drop 0.1

tion in the cold. The compounds obtained and- The new esters in comparison with the known The followingexamples illustrate the invention,

and the whole is heated for some time at C.

part of hydroxide in 2 parts of methanol. The whole is allowed to stand for 2 days.

, The methanol is now evaporated in a vacuum and theresidue taken up with parts of water. The aqueoussolution is, then extracted with ether to remove unsaponified diester. On acidifying the aqueous solution with N/2sulfuric acid there is obtained an oil which is extracted with ether,

the ethereal solution being then washed with sodium bicarbonate solution and subsequently evaporated. By crystallizing from dilute methto rest overnight at room temperature. .It is then mixed with 100 parts of water and the oil 3 which is precipitated is extracted with ether. The ethereal solution is washed with N/sulfuric acid, water and N/lO-caustic soda solution in succession and then evaporated to dryness. .The

residueis recrystallized from dilute methanol to obtain uzed-diethyl -4' :4 dihydroxy diphenylethane+propionate-butyrate. g

, "'Ezcampleiij. i 1 part oi e:s'-diethyl-4' :4"-dihydroxy-diphenylethane is dissolved in 10 parts of quinorlne and to the solution there are added by drops 6 parts a of caproic acid chloride; the whole is then allowed to stand at room temperaturegfor 24 hours. It is then extracted with ether, the ethereal soluerecrystallizedtrom dilute ethanol. Melting point tion washed with dilute sulfuric acidand sodium j hexadiene is heated in 15 parts of pyridine with 5 parts of propionic acid anhydride for some time at about 50 C. The whole is then cooled and mixed with water whereby an. oil is caused to separate. This is dissolved in ether and the ethereal solution is washed successively with N- sulfuric acid, water and N/lO-caustic soda solution. The dipropionate remains on evaporation of the ether and may be recrystallized from aqueous ethanol.

' Example 6 A solution of I part or a:a'-diethy1-4':4"-dihydroxy-diphenylethane in 5 parts oi. pyridine is added by drop to a strongly cooled solution of- 2 parts of. hosphorusoxychloride in 5 parts 05 pyridine. The mixture soon solidifies to a thick magma. It is left in ice for hour and then allowed to stand for 1 hour at room temperature. Next it is poured into saturated sodium bicarbonate solution and unconsumed parent material 'is extracted by means of ether. By acidifying theaqu'eous liquid the phosphoric acid di-ester is precipitated in the form of a white voluminous powder. By reprecipitation this ester may be further purified. r

1 part of the primary phosphoric acid ester thus obtained is dissolved in 5 parts of water and there are added 0.2 part of sodium hydroxide in 1.25 parts of water. The clear solution is, now evaporated to dryness in a vacuum whereby the water-soluble sodium salt oi. the'ester is obtained.

In an'analogous manner .the secondary and tertiary phosphoric acid di-esters may be obtained.' I

The manufacture of the phosphoric acid diester of 314- (4' :4"-dihydroxy-diphenyl) -2 :4-

hexadiene and its alkali salts falls on the same 'lines.

- In. an analogous manner may be made the 40 caproate of 4:544 :4'--dihydroxy-diphenyl) -3 ;5-

octadiene.

I I Examplel 1 part of uz d-diethyh-':4"-dihydroxy-diphen- Methane is dissolved in 25 parts of 2 N-caustic.

soda solution. This solution is shaken with 2 parts of benzoyl chloride until the smell of the acid chloride is no longer detected. The benzoic acid ester producedgis filtered; when recrystal-.

alcohol it melts at 235-237 C.

lined from propyl Example 5 i This application is a division of our application Serial No. 285,018, filed July 1'7, 1939. 'Whatweclaimisr Y 1. The phosphoric-acid di-esters of a:'-diethyl-4':4"-dihydroxy-diphenylethane.

2. The primary diphosphate of azd-diethyl- 4':4"rdihydroxy-diphenylethane.

-3. A compound selected from the group consisting of the phosphoric and sulfuric acid iii-esters of azd-dialkyl-dihydroxy diphenyl ethane and of azd-dialkenyl-dihydroxy diphenyl ethane.

' KARL mnscnnn.

JULES HEER. 

